The WCH CH397A is a USB interface controller developed by WCH (QinHeng Electronics), designed for high-speed data communication and peripheral expansion applications. It provides a reliable USB 2.0 interface and is commonly used in industrial control systems, embedded development boards, and USB-based adapters. The CH397A supports multiple data transfer modes and integrates internal logic to simplify firmware and hardware design. Known for its stability and cost-effectiveness, it is often chosen for custom USB devices that require dependable connectivity with Windows and Linux systems, typically using dedicated WCH drivers for proper recognition and operation.